A050236 - OEIS

A050236

Indices of consecutive squares palindromic primes; x such that x^2 + (x+1)^2 is palindromic and prime.

1, 9, 12, 1262

(list; graph; refs; listen; history; text; internal format)

OFFSET

1,2

COMMENTS

No other terms < 20000000000. - Patrick De Geest, Aug 15 1999

LINKS

Table of n, a(n) for n=1..4.

Patrick De Geest, Palindromic Sums of Squares of Consecutive Integers

Carlos Rivera, Puzzle 14. Pal-Primes and sum of powers, The Prime Puzzles & Problems Connection.

Eric Weisstein's World of Mathematics, Palindromic Prime

MATHEMATICA

Flatten[Position[Total/@Partition[Range[1300]^2, 2, 1], _?(PrimeQ[#] && IntegerDigits[#]==Reverse[IntegerDigits[#]]&)]] (* Harvey P. Dale, Dec 09 2014 *)

PROG

(PARI) isok(m) = my(p=m^2+(m+1)^2); if (isprime(p), my(d=digits(p)); (d == Vecrev(d))); \\ Michel Marcus, Jan 05 2019

CROSSREFS

Cf. A050239.

Intersection of A027861 and A027571.

Sequence in context: A188001 A273614 A281224 * A193995 A070607 A340490

Adjacent sequences: A050233 A050234 A050235 * A050237 A050238 A050239

KEYWORD

nonn,nice,hard,base

AUTHOR

Eric W. Weisstein

STATUS

approved